L Laurentiu Encica

Electromagnetic and Thermal Design of a Linear Actuator Using Output Polynomial Space Mapping

This paper describes the optimization methodology used in the design of a slotted tubular permanent-magnet actuator for industrial applications. A time-effective optimization procedure is obtained by considering simple analytical design equations in coherence with 2-D finite-element analysis as means to establish the various design variables. The optimization is performed in a multiphysics environment because both electromagnetic and thermal models are created and used in the optimization routine. The original optimization problem is replaced by a surrogate, which is updated or improved iteratively by means of a space-mapping-based technique. Its application for solving coupled magnetic-thermal design problems for electric machines is a rather unexplored topic.

Design Considerations for a Semi-Active Electromagnetic Suspension System

Vehicle manufacturers always strive to improve the vehicle handling and passenger safety and comfort. One of the focus points for the automotive industry is the (semi-)active suspension system for which various commercial technologies are existing, varying from pneumatic to hydraulic. This paper addresses the design considerations of a tubular electromagnetic actuator for semi-active suspension

Aggressive Output Space-Mapping Optimization for Electromagnetic Actuators

Automated electromagnetic actuator design can be achieved by means of several approaches. For example, one might consider fast, however, accuracy deficient coarse models or, in contrast, the design could be achieved exclusively by employing accurate, time expensive, fine models. The space-mapping optimization technique, with its input or output mapping based implementations, merges the advantages of the two extremes. A new algorithm variant that presents a simple structure, namely the aggressive output space-mapping, is proposed in this paper. The design problem of a tubular permanent magnet actuator is considered in order to compare the proposed algorithm with two existing techniques.

Tooth contour method implementation for the flux-switching PM machines

Flux-switching machines are attracting interest among researchers over the last decade due to the increased importance of energy efficient systems. Among this class of machines, the rotary flux-switching PM machines (FSPM) with high power density are mostly analyzed by magnetic equivalent circuit (MEC) and finite element methods (FEM). In addition to those analysis techniques, this paper introduces the implementation of the tooth contour method (TCM) for the first time for a rotary FSPM. During the modeling phase, many points are revealed which are essential for the electromagnetic behavior of this unconventional machine.

Analysis of a novel double sided flux switching linear motor topology

A novel three-phase double sided flux switching linear motor topology with a stator-to-mover teeth ratio of 19/24 is presented. Finite element analysis of the electromagnetical performance of the initial design is conducted and shows that the topology suffers from an unbalanced EMF in terms of amplitude and phase shift between the three phases. On the other hand a low detent force is observed. By adding end-teeth to the structure, a balanced EMF is obtained, but the detent force also increases. A geometrical optimization is conducted on the end-tooth shape and stator tooth width to reduce the detent force while maintaining a balanced sinusoidal EMF. For the optimization a faster hybrid modeling tool is used. The hybrid model is based on the magnetic equivalent circuit method that employs the boundary element method to accurately determine the air gap permeances of the magnetic equivalent circuit.

Comparison of winding topologies in a pot core rotating transformer

This paper discusses the comparison of two winding topologies in a contactless energy transfer system from the stationary to the rotating part of a device. A rotating transformer, based on a pot core geometry, is proposed as a replacement for wires and slip rings. An electromagnetic and a thermal model of the rotating transformer are derived. The models are combined and used in a multi-objective optimization. A Pareto front, in terms of minimal volume and power losses, is derived to compare both winding topologies. Finally, the optimization algorithm is used to design a prototype transformer for each winding topology, which are manufactured using a commercially available pot core.

Optimisation in electromagnetics with the space-mapping technique

Purpose – Optimisation in electromagnetics, based on finite element models, is often very time‐consuming. In this paper, we present the space‐mapping (SM) technique which aims at speeding up such procedures by exploiting auxiliary models that are less accurate but much cheaper to compute.Design/methodology/approach – The key element in this technique is the SM function. Its purpose is to relate the two models. The SM function, combined with the low accuracy model, makes a surrogate model that can be optimised more efficiently.Findings – By two examples we show that the SM technique is effective. Further we show how the choice of the low accuracy model can influence the acceleration process. On one hand, taking into account more essential features of the problem helps speeding up the whole procedure. On the other hand, extremely simple auxiliary models can already yield a significant acceleration.Research limitations/implications – Obtaining the low accuracy model is not always straightforward. Some resear...

Human-powered small-scale generation system for a sustainable dance club

Most human powered energy harvesting systems are used to power ubiquitously deployed sensor networks and mobile electronics. These systems scavenge power from human activity or derive limited energy from ambient heat, light, or vibrations. In most of these conventional methods users must focus their attention on power generation at the expense of other activities. However, for sustainable electrical power generation, energy could be harvested from everyday activities such as walking, running or even dancing. In this paper systems are analyzed that use human power by walking, or running, where an alternative system has been designed and implemented that generates energy from people dancing in a club environment. It will be shown that powers exceeding walking can be extracted from the system, i.e., maximum 80–100 W or an average of 20–30 W over a time period of 10 s.

Space‐mapping optimization in electromechanics: an overview of algorithms and applications

Purpose – The space‐mapping (SM) optimization technique, with its input, implicit or output mapping‐based implementations, provides a basis for computationally efficient engineering optimization. Various algorithms and design optimization problems, related to microwave devices, antennas and electronic circuits, are presented in numerous publications. However, a new application area for SM optimization is currently expanding, i.e. the design of electromechanical actuators. The purpose of this paper is to present an overview of the recent developments.Design/methodology/approach – New algorithm variants and their application to design problems in electromechanics and related fields are briefly summarized.Findings – The paper finds that SM optimization offers a significant speed‐up of the optimization procedures for the design of electromechanical actuators. Its true potential in the area of magnetic systems and actuator design is still rather unexplored.Originality/value – This overview is complementary to ...

Passive and active constant force-displacement characteristics and optimization of a long-stroke linear actuator

In applications such as vibration isolation, gravity compensation, pick and place machines, etc., the applicability of commercial low force passive devices is limited and hence would benefit from an improved and preferably variable force level. This paper presents and investigates such a long stroke constant-force versus displacement actuator topology, where analytical and equivalent circuit models are detailed and compared with comprehensive three dimensional (3D) finite element analyses. Furthermore, the optimization of such an actuator by means of aggressive output space mapping is considered. This technique employs a combination of a single analytical equation and a 3D finite element model. Specifically, the optimization is applied to obtain a passive and active force level of 200 N and 300 N, respectively, where the force- displacement response is constant over 60% to 90% of the total stroke.